1. Field of the Invention
This invention relates to a device for facilitating the in-situ treatment of sediments, especially the bioremediation of sediments containing hazardous organic wastes, by simultaneously agitating, aerating and introducing nutrients, microorganisms or chemicals such as oxidizing agents or detergents into the sediments.
2. Description of Prior Art
The treatment of sediments containing hazardous wastes has, heretofore, generally involved the removal of the sediments for treatment or for disposal at an approved disposal site. Treatments have included air striping, solvent extraction or microbial degradation of the hazardous material before depositing the sediments in a suitable location (EPA/600/S2-86/112 Mar. 1987). Treatment of sediments has been limited by the lack of an economical device for mixing appropriate microorganisms, nutrients, oxygen or treatment chemicals with the sediments bearing target substances without removing the sediments from their original location. An air chain device was described in U.S. Pat. No. 4,797,212, but the device was designed for use only in wastewater treatment basins and does not provide for the introduction of microorganisms, nutrients or treatment chemicals into the sediments. The air chain would function properly only in soft unconsolidated sediments as its bottom aerators are suspended above the floor of the treatment basin. A device which discharges a mixture of gas and liquid into ambient water for biological treatment is presented in U.S. Pat. No. 4,69764, but it is fixed to the side of treatment basins and no provision is described for it's use in the treatment of sediments.
There is an continuing need for an inexpensive, portable device that can penetrate dense, compact, anaerobic sediments and mix with them oxygen, nutrients and microorganisms, or chemicals such as oxidants and detergents.